Liquefied gas filler and eduction device



March 30, 1965 H. N. SHAW 3,175,579

LIQUEFIED GAS FILLER AND EDUCTION DEVICE Filed April 30, 1963 sSheets-Sheet 1 FIG. I

INVENTOR.

HARRY N. SHAW March 30, 1965 H. N. SHAW 3,175,579

LIQUEFIED GAS FILLER AND EDUCTION DEVICE Filed April 30, 1963 sSheets-Sheet 2 all/111111111 l N VEN TOR .Iulllllll March 30, 1965 r H.N. SHAW LIQUEFIED GAS FILLER AND EDUGTION DEVlCE Filed April 50, 1963 3Sheets-Sheet 3 INVENTOR.

HARRY p1. SHAW United States Patent 3,175,579 LIQUEFIED GAS FILLER ANDEDUCTION DEVICE This invention relates in general to fluid filling andemptying systems for handling liquefied gas in bulk storage andtransport containers which are generally of a cylindrical shape, andmore particularly to a fillereduction safety cut-off valve constructionwhich provides all the safety advantages of excess flow valves withoutsome of their disadvantages of normal openness and large pressure drops,and also includes the safety advantages of an overriding positiveshut-off valve which is located protectively inside the container yetcan be remotely controlled both manually and automatically to close oropen automatically during the filling or dispensing of gas in its liquidphase as part of a closed system in which operating pressures arepresent or are developed with the liquefied gas being handled.

For many years the manufacturers and users of liquefied petroleum gashandling equipment have been concerned about the problem arising withstarvation on the inlet side of their eduction pumps when high capacitypumping is desired for emptying a storage container with sufiicientrapidity for such to be economical. 7

Where water remains liquid at the intake of a pump when cavitationcondition might develop, liquefied gas presents an aggravated problem.Liquefied gas such as propane or butane have low boiling points and atnormal atmospheric temperatures they have sufiicient sensible heatavailable to furnish substantial amounts of latent heat of vaporization.Therefore, under liquid solid conditions liquefied gas is quitesensitive to vaporization with drops in pressure that may be induced indispensing conduits ahead of pumps. A slight drop of pressure below thevapor pressure even before lower cavitation pressures are reached causesvaporization that forms gas pockets. Such pockets as well as cavitationat the pump blades is harmful to the pump.

Now, if a positive hydraulic head can be maintained upon liquefied gasat the pump inlet, i.e., a pressure above the vapor pressure in thetank, the pumping conditions can be greatly improved sincethe pump wouldnot be required to draw liquefied gas from the container to which it isconnected under conditions causing vaporization and cavitation. However,the excess flow valves now provided for safety purposes in eductionconduits leading to pump intakes depend upon a substantial pressuredifferential to operate. Such differentials have to be built into thedesign of excess flow valves notwithstanding the fact that the requireddifferential drop across the excess flow valve is a liability at highpumping rates. Slow pumps have to be used because pumps fast enough tobe economical often exceed the flow characteristics for which the excessflow valves are designed and the valve repeatedly snaps closed. Thisgenerally occurs irrespective of the head pressure above the valve.

However, since the downstream rate of flow is what influences thepressure drop differential occurring at the excess flow valve, it hasbeen noted that if the downstream flow rate is kept constant and withinthe capacity of the valve the pressure drop differential increases asthe tank approaches empty. The flow is gradually being starved at thevalve as long as it is open because of a decreasing head pressure at thevalve inlet. Thus, head pressure loses its helpfulness as soon as itbecomes less than the presure drop acros the valve. The greater that thepressure drop across the valve exceeds the hydraulic head, the greaterwill be the tendency for the pump intake to cause vaporization andcavitation.

For instance, assume two valves rated for identical intallation with onevalve designed for a one pound pressure drop differential to close as anexcess flow valve while the other valve designed for shut-off has apressure drop of only one quarter pound for the same rate of flow ofapproximately gallons per minute. It will be observed that approximatelya four foot hydraulic head, or more, of liquefied gas is required tomake up for the one pound pressure drop a maintain a liquid solidcondition at the pump intake without vaporization dangers, whereas, withthe other valve anything over a one foot head will maintain a liquidsolid condition at the pump intake.

Thus, with most cylindrical tanks large enough to provide an initialhead over four feet, the desired head pressure is lacking except for avery small amount of liquid dispensed before the hydraulic head fallsbelow the four foot mark and thereafter vaporization becomes anincreasing danger. The pressure between the valve and pump increasinglyfalls below the vapor pressure and there still would be a major portionof liquid left to be educted. The level of the liquid would drop quicklydown to the four foot depth and after that very slowly even thoughprogressively more rapidly as the bottom is approached below the halffull level.

Although air pressure can be added to assist the diminishing hydraulichead, such pressure being additive, the effective tank pressure would beintolerably high when full in order to have there quarters of a poundremaining to be efiective as a supplement to hydraulic head when onlyone foot of liquid remained in the tank. On the other hand, if onlyenough air is added to assist the last foot of liquid in the containerwhere only a slight valve pressure drop of one quarter pound is presentits additive pressure would be only two pounds above vapor pressure witha half full tank and approximately eight pounds when the tank is filledto the usual 10 percent outage. Thus, this mild assist pressure is quitetolerable. It is not too high for tank ratings and it is substantiallyunchanged by temperature, yet safely assists in providing an effectivehead much higher than the hydraulic head alone could provide with a fulltank and a high rate of fiow would not be confronted with a valveclosure. How ever, for a remaining one foot hydraulic head with solittle remaining volume in the tank yet to be educted the need for ahydraulic pressure assist is virtually eliminated by the presentinvention.

Moreover, comparatively speaking, where conventional filler-eductionexcess flow check valves are designed to have as much pressure drop ascan safely be possible yet interfere with pump capacity as little aspossible, it is to be observed that the present invention is virtuallyopen to full flow with comparatively no pressure drop that materiallyaffects the pump. Additionally, it is controlled to close automaticallyinstantly with greater sensitivity to pressure drops caused by fluidescaping through small breaks up to and even beyond the pump.

Accordingly, one of the objects of the present invention is to provide asafety cut-ofl? valve for performing excess flow valve functions wherethe drop of pressure across the valve itself is very slight andtherefore, only a slight hydraulic head is needed to maintain a positivehead pressure to maintain a liquid solid prime at the pump intake.

Another object of the invention is to provide a fillereduction valvewith which a positive head pressure will be provided for the intake ofeduction pump throughout substantially all of the tank emptying pumpingoperation whereby operating factors without vaporization or cavitationare greatly improved for high volume pumps.

A further object of the invention is to provide a liquid eduction safetyvalve that is controlled manually to open and close and to close or bereleased to open either inechanically or hydraulically by application ofpressures developed or present in the system with or without the pumprunning.

Another object of the invention is to provide a liquid filler-eductionvalve that opens against the outflow of liquid from the tank by feedback of eduction pump output pressure to the valve actuating'mechanism.

It is a further'object of this invention to provide an improved, light,unitary, self-contained valve and pump apparatussecured to a transporttank which rapidly educts the fluid from the tank with full safetyWithout reliance on eXternal or excess flow control valves.

Another object of this invention is to provide an improved, fullyautomatic, internally mounted fiow cut-off valve coupled with a highcapacity pump which valve 7 automatically assumes the closed positionuntil the pump is started, thereby precluding over-the-road travel withan open valve yet can be opened manually if the pump fails to start.

A further object of this invention is to provide an improved valveinternally mounted in a tank for fluid control having a visual indicatordenoting whether the valve is in the open or close position.

Another object of this invention is to provide an improved, fullyautomatic, internally mounted flow control valve coupled with a highcapacity pump and valve arrangement ofrminimized weight to be carriedbeneath a bulk tank whereby the tank may be filled or drained withminimum time and expense.

Another object of this invention is to provide an improved liquidemptying and filling apparatus that is simple in design, rugged inconstruction, economical to manufacture, adaptablefor mounting onexisting tanks or new construction, completely self-contained tocomplete a fluid filling or eduction operation and provides maximumsafety and fail-safe operational characteristics.

Still another object of this invention is to provide an improved,automatically operated flow valve, having looking means whereby thevalve can be secured against opening by back pressure from a manifoldand a similar valve 7 operating from another compartment or container.

Further objects and advantages of the invention will be readily apparentfrom the following detailed descrip-- tion of a specific embodiment ofthe invention with references made to the accompanying drawings inwhich:

FIG. 1 is a fragmentary partially sectioned schematic view showing thevalve control and system incorporating a pump andvalve for a typicalutilization of the invention;

FIG. 2 is a fragmentary partially sectional side elevational Viewillustrating the draining and filling apparatus of this invention andthe position of the component parts of the valve when in the closedposition;

FIG. 3 is a partially sectioned bottom view of the draining and fillingapparatus illustrating the relationship of certain components on thelower portion of the apparatus;

FIG; 4 is a linear view of the locking and unlocking means showing theparticular components over 180 of rotation; and v I g FIG. 5 is afragmentary view similar to FIG. 2 showing a modification of the deviceshown therein. g

The invention is characterized by a liquid filler and eduction valvenormally closed by a spring'in the direction of outflow from a tankwithin which it is protectively mounted 'at the bottom thereof. Thevalvecan be rotated with respect to its seat and the valve stem, and thevalve stem is rotatably supported and extends outwardly through the wall'of'the tank to move the valve between two positionary cam rise and theother in which it is released to open over a cam relief. The stem isalso rotatably received through a diaphragm which longitudinallydisplaces the valve stem for actuation of the valve in which a pressureon the lower side of the diaphragm is higher than that present on theupper side to open the valve, while. a balance of pressures on oppositesides either of high or low pressures permits the spring to close thevalve.

The upper diaphragm chamber maybe supplied with pressure when present inthe valve outlet through an orifice or supplied with tank pressure abovethe valve through a pilot valve control to close the valve or can hevented to atmosphere for opening the valve. The lower diaphragm chambermay be supplied with pump outlet superior to the valve outlet pressureor with tank pressure by pilot valve to open the valve when the upperchamber is vented to atmosphere and to close the valve when the lowerchamber is vented to atmosphere or both chambers have equalizedpressures.

Referring now to the drawings in further detail, a valve 1 is mounted atan opening 2 in the bottom of a tank 3 with its outlet 4 connected byconduit 5 to the inlet 6 of pump 7 which has an outlet 8. The valve 1comprises a valve body 29 (FIGS, 1 and 2) which has a cylindricalinverted cup-like cap 9 marginally threaded at 27 to a male couplingthread on the body 29 bordering a valve seat 22. At the top of the cap92. boss 13 is provided with a central bore 11 which reciprocablyreceives rotatably therein a stub shaft 14 having a crosshead 16therebelow supporting a shaft zl that journals cam follower rollers 15to follow an aXial cam surface 23 on a cam ring 10 that bottoms on ashoulder 28in the cap 9 and has a detent 3211 at the top of the cam rise32 (FIG. 4). V A compression spring 12 engages the crossheadlfi andurges it downwardly whereby a valve head 19 journalled on a stud 39below the crosshead 16 is urged to close against the valve seat 22through a'b earing washer 17 made of amaterial having a low frictioncoeflicient. The lower end of the stud 30 is machined to provide awrenching surface 25. v

'Below the valve seat 22 a main shaftfi'l is journalled in the body 2%as later described and has a wrenching socket 31 telescoping over thesurface 25 as supported in engagement therewith by an external springwasher 18 resting on top a flanged collar 26 threaded to the valve head19 to also hold the valve disc 20 in place. There is very little endplay between the shafts 14 and 37, consequently movement of the mainshaft 37 operates with the stub shaft 14 as a unitary valve stem for thevalve 19. The valve in turn is rotatably mounted on the stern so thatstem can open and close the valve without rotation of the valve withrespect to the valve seat. The valve disc 29 is thick enough thatresiliency thereof permit the rollers 15 to attain the detent's 32a andhold them there. Thus, when the cam rollers 15 are on the cam rise 32 inthe detent 32a, the stem cannot be moved axially to open the valve, butwhen the'rollers 15 are over the cam reliefs 33 the stem is free to openand close the valve, yet the cam rollers can be turned any timeto'mechanically forceclosure of the valve even from its open posi- 7tion. Openings 24 through the wall of the cap 9 peropenings a spaceddistance therefrom to prevent solid particles from damaging the valvedisc.

Just below the valve seat 22 the body 29 can be mounted in sealedrelation in the opening 2 in thetankS either by a threaded joint 35arrangement (FIG. 2) or as shown in FIG. lby a flange and bolt mounting41. Flange mounting is preferred forready orientation of the valve.

Below the tank mounting 41 the body is shaped generally as an elbowfitting with a right angle passage 60 therethrough and with the outsidewall 42 thereof contoured and recessed to provide a diaphargmcompartment having a threaded opening 43 through the crown thereofdisposed coaxial with the seat 22 and in communication with the passage60. The shaft 37 is received through this opening as journalled inguided relation by a threaded collar 46 supporting a bearing member 47which has small longitudinal interior grooves 45 facing the shaft topermit restricted communication between the passage and compartment 50.

Closinng the mouth of the compartment 50 is a diaphragm 52 clamped inplace by a bonnet held by bolts 71 and having an area exposed on thelower side appreciably greater than the area defined by the valve seat22. The diaphragm 52 is apertured to receive the shaft 37 therethroughand is provided with a diaphragm collar 73 having an O-ring seal 76engaging the shaft 37. The diaphragm is secured in sealed relation tothe collar 73 by a washer 74 and nut 75 secured to the collar. Thecollar has a bleed orifice 53 (FIG. 2) through it and the shaft has ashoulder 51 and a spring washer 72 which couples together the verticalmovement of the diaphragm and shaft 37 to dispose the diaphragm in itslower position when the valve is closed.

The bonnet 70 defines a chamber below the diaphragm 52 and has a centralopening 97 receiving a collar threadedly therein for journalling theshaft 37 in a relationship sealed by a gasket 102. The collar extendsbeyond the bottom of the bonnet and into a circular cavity 98 providedin the bottom wall 99 where it loosely supports in threaded relationshipa socket wrench member 103 having a handle 120 on it for actuation and asocket 100 slidably receiving the squared lower end 106 of the shaft 37for rotating the shaft thereby.

The periphery of the socket member 103 is journalled in the circularcavity 98 and has a groove 96 therein provided with camming rollerswhich displace outwardly a pilot valve stem 104 that radially intersectsthe groove. The stem when displaced opens a normally closed valve 91that is threaded into the side wall of the bonnet to vent the bonnetchamber 80 to atmosphere through passages 81 and 93 drilled in the walland the stem 104, respectively. The valve 91 can be assembled andserviced by removal of a back cap 94. Whenever the valve 19 opens, thelower end of the stem 37 disappears within the socket member 103 toserve as an indicator that the valve 19 is open.

Lugs shown at A and B (FIG. 3) limit the movement of the handle to anangle of 90 and as shown in broken lines, the cam rollers 110 engage therelief valve piston 104 when the handle is passing from its open" to itsclosed position against lug A. This engagement frees the relief valve toclose at both limits of its movement. Thus, when the valve 19 is beingclosed, the vent valve 91 is momentarily opened to vent chamber 80 sothat no hydraulic perssure can be built up in the chamber 80 that wouldoppose the diaphragm movement when the valve 19 is moved to its closedposition, and then closed again so that no liquefied gas is lost to theatmosphere.

When the handle 120 is in open position, pressure can be supplied to thechamber 80 through any one of a number of nipple connections.

The outlet end of the body 29 is threaded as at to receive the conduit 5leading to the intake 6 of a pump 7 having an output connection 8. Itwill be observed that the pump is connected and is designed to pumpliquid. Accordingly, it is desirable that the intake of the pump beprimed with liquid before it is started. The invention provides forseveral ways to do this through a conduit 36 drilled in the body 29 downto a threaded opening 39 to take liquid from the tank.

The preferred way is to bottom drill the opening 39 into the passage 60to provide a conduit 84 by passing the valve 19 and threading a needlevalve plug 40 into the opening to adjust for a continuous bleed ofliquid from the tank to the passage 60 to keep the passage 60 and pump 7primed.

A connection 82 leads from the output side 8 of the pump 7 so that oncethe pump is started, the output pres sure of the pump is effective inchamber 80 and opens the valve 19. However, in event there is a break inthe pump output hose, the output pressure drops. Then the compartment isno longer supplied at an output pressure above the pump intake pressureto which the upper compartment 50 is subjected and the diaphragm isquickly balanced on opposite sides through the bleed passage 53.Thereupon the spring 12 assisted vw'th the outflow of liquid through thevalve closes the valve 19 in seconds. Thus, a very slight drop in pumpoutput pressure operates to close the valve, thereby providing a verysensitive but full flow safety shut-off valve arrangement.

It is desirable to provide a manual shut-off valve 83 in the connection82 which is normally left open but when an emergency arises can beclosed to actuate the closing of the valve 19 with the same as though abreak had occurred in the pump outlet 8.

In addition to the vent valve 91 a safety line 105 can be extendeo torun to an operators station or to other critical points around the tankwhere hand operated vent valves 101 may be located whereby the pressurein compartment 80 can be vented at any one of a number of stations toclose the valve 19.

Referring to FIG. 5, a modification is shown in which the bleederpassage 53 (FIG. 2) can be eliminated and whereby the chamber 50 can bevented to atmosphere so that the valve 19 can be opened independently ofa pump 7 by the pressure present in the lower chamber 80. This willprovide two results. It will liquid prime the passage 60 by freeingvapor present below the valve 19 to bubble up into the tank 3, and withthe valve 107 (FIG. 1) open liquid can be educted under continuousmanual attention by gravity without the pump running.

Either the plug 119 (FIG. 2) can be removed if continuous venting isdesired or preferably, the passage 36 can be extended as at 36a to thethreaded opening 121 provided through the wall of chamber 50 ifpressures are to be applied on both sides of the diaphragm 52. In whichcase, a dual acting valve arrangement (FIG. 5) is threaded therein andcomprises a plug 122 having a cylindrical cavity 123 in the inner endthereof slidably receiving a piston sleeve valve element 124a thereinsealed by an O-ring 125. The valve element 124 has a hexshaped externalcontour 126 at its inner end shouldered to stop against the end of theplug in open position and faced off on its end face to close against avalve seat at 127. This controls the flow of replenishing or equalizingfluid through conduit 36a to the chamber 50.

A Dill valve 128 is threaded into the valve end of the valve element 126with its stem 129 exposed to contact with a removable pin 131 extendingthrough a spider 132 in the plug at the bottom of a cavity 133 in itsouter end and vented to atmosphere through lateral holes 134 in thesides thereof. Insertion and finger pressure on the head 135 of the pin131 initially moves the piston sleeve valve 124 to its closed positionto seal off conduit 36a and further movement of the pin opens the Dillvalve 128 to vent chamber 50 to atmosphere through the spider 132 andvent holes 134. Thereupon the pressure in the chamber 80 below thediaphragm 52 opens the valve 19 for as long as the head 135 is manuallydepressed. When the pin 131 (and head) is released, the Dill valvecloses, and pressure bleeding through the passage 36a causes the pistonsleeve valve 124 to open for quick application of tank pressure to thechamber 50 to close the valve 19 again if the pump is not running.

Whenever the chamber 50 is vented to atmosphere in FIG. 5, the use ofthe vent valve 101 (FIG. 1) or the handle 120 operates to vent chamber80 to equalize pressures on opposite sides of the diaphragm whereby thespring 12 closes the valve 19.

compartment is vented to atmosphere.

' In operation it will be observed that a hydraulic head is imposed uponthe pump intake to maintain a pressure preventing vaporization orcavitation at the pump intake to assure a liquid solid conditionthroughout allconduits connected to the pump including the outlet up toa manual shut-oil? valve 107. Then when the pump is started, the outputpressure is forced up much higher thanrthe intake pressure and this isinstantly effective in the compartment 8t) whereupon with the handle 120located at open position, the diaphragm, stern, and valve 19 are raisedto their open position. Thereupon the manual shut-oil valve 107 isopened for pumping operations to proceed. The valve 19 has littlepressure drop and the pump intake continues its liquid solid prime.Thereafter the valve 19'is closed by venting pump output pressure incompartment 80 or by equalizing pressures on opposite sides of thediaphragm to an extent whereby the spring 12 is capable of closing thevalve 19.

Consequently, it will be understood by those skilled in the art how theobjects of the invention are attained and how various and furtherchanges may be made in the valve system described without departing fromthe spirit of the invention, the scope of which is commensurate with theappended claims.

What isclaimed is: 1. A liquid eduction device comprising a tank forstoring liquefied gas in both its liquid and vapor phases, outlet means.for said tank including a'valve housing having a valve seat facing thetank in communication with said tank at the bottom thereof and subjectedto the hydraulic head of the liquid in said tank in addition to thepressure in the tank of the vapor thereon, a valve member closingagainst said valve seat and including a rotatable stem, means forclosing the valve including an element resiliently closing the valvemember and a cam member operated by rotation of said stem for positivelycloslng the valve member, a liquid pump connected at its inlet to thevalve seat and having an outlet with a shut-off valve therein, a bleedpassage bypassing said valve head and seat forliquid priming of the pumpinlet, pressure responsive means for reciprocating said valve stemincluding a diaphragm, means for applying to one side of the diaphragmliquid pressure from the output side of the pump to open said valve andincluding a shut-off valve, means for venting said liquid pressure, andmeans for applying to the other side of the diaphragm liquid pressurefrom the inlet of said pump to urge closure of the valve.

2. A liquid eduction device comprising a tank for storing liquefied gasin both its liquid and vapor phases, outlet means for said tankincluding a valve housing having a passage therethrough including avalve seat of the same size as the passage facing the tank incommunication with said tank at the bottom thereof and subjected to thehydraulic head of the liquid in said tank in addition to the pressure ofthe vapor thereabove, a cap supported on said housing having valve inletopenings at the level of said valve seat, a valve head closing againstsaid valve seat including a stem rotatably and reciprocably supported bysaid cap, means for closing the valve including a resilient memberresiliently closing and a cam member operated by rotation of said stemfor positively closing the valve head, said members being supportedwithin said cap above said valve head, a liquid pump connected at itsinlet to the passage and having an outlet, a bleed passage bypassingsaid valve head and valve seat for liquidpriming the pump inlet,pressure responsive means for reciprocating said valve stem including adiaphragm, means for applying to one side of the diaphragm liquidpressure from the output side of the pump to open said valve, means forventing said liquid pressure includinga valve'actuated by rotation ofthe stem to close the valve head for reducing the pressure to below thetank pressure at said inlet openings, and means for applying to theother side of the diaphragm liquid pressure from the inlet of said pumpto urge closure of the valve.

3. A liquid eduction device for a tank storing liquefied gas in both itsliquid and vapor phases comprising outlet means attachable to said tankincluding a valve housing having a valve seat facing the tank incommunication with said tank at the bottom thereof and subjected to thehydraulic head of the liquid in said tank in addition to the pressure ofthe vapor thereon, acap on said housing having openings at the level ofsaid valve seat, a valve head closing against said valve seat includinga rotatable stem reciprocably supported in said 'cap, means carried bysaid cap for closing the'valve including a resilient element resilientlyclosing and a cam member operated by rotation of said stem forpositively closing the valve head, a liquid pump connected at its inletto the valve seat and having an outlet with a shut-01f valvetherein, ableed passage bypassing said valve head and seat for liquid priming ofthe pump inlet, pressure responsive means for reciprocating said valvestem including a reciprocating member, means for applying to one side ofthe reciprocating member liquid pressure from the output side of thepump to open said valve, means for venting said liquidpressure, meansfor applying to the other side of the reciprocating member liquidpressure from the inlet of said pump to urge closure of the valve, andbleed means bypassing said a reciprocating member tending to equalizeliquid pressures or opposite sides of the reciprocating member.

4. ,Afquick acting cut-ofi filler-eduction valve for liquefied gasstored in both its liquid and vapor phases comprising a valve bodydefining a passageway having a valve seat therein in communication withliquid phase gas, a valve head closing against said seat and having astem extending through the valve seat, resilient means urging said valvehead to closed position, a bleed conduit bypassing said valve and, valveseat to maintain gas in its liquid phase in said passageway, pressuredifferential responsive means including a reciprocating member connectedto the valve stem, means for applying a pressure higher than thatpresent in the passageway to one side of said pressure responsive meansto urge it to open the valve, means assisting said resilient means forapplying pressure in said passageway against the other side of saidpressure responsive means to urge it to close the valve when said higherpressure drops below a predetermined diiferential between the twopressures, manual means for closing said valve, and means controlled bysaid manual means for venting said one side of said pressure responsivemeans before the manual means closes said valve.

5. A quick acting cut-off filler-eduction valve comprising a valve bodydefining a passageway having a valve seat therein, a valve head closingagainst said seat and having a stern extending through the seat,resilient means urging said valve head to closed position, a bleed'conduit bypassing said valve and valve seat for equalizing pressures onopposite sides thereof in their closed position, pressure diiferentialresponsive means including a reciprocating member connected to the valvestem, means for applying a pressure higher than that present in thepassageway to one side of said pressure responsive means to urge it toopen the valve, means for applying pressure in said passageway againstthe other side of said pressure responsive means to urge it to close thevalve-when said higher pressure applying means ceases, bleed meansinterconnecting opposite sides of said pressure responsive means tendingto equalize pressures on oppositesides thereof, manual means for lockingsaid valve head in closed position closing said valve, and meanscontrolled by said manual means for venting said one'side of saidpressure responsive means before the manual means closes said valve.

6. A quick acting cut-01f filler-eduction valve comprising a valve bodydefining a passageway having a valve seat therein and inlet openingsaround said valve seat, a valve head closing against said seat androtatably receiving a stem extending through the seat, resilient meansabove said valve head urging said valve head to closed position, cammeans actuated by rotation of said stem for locking said valve head inclosed position, a bleed conduit bypassing said valve and valve seat tomaintain said passageway liquid solid, pressure differential responsivemeans including a reciprocating member connected to the valve stem,means for applying a high pressure present in the passageway to one sideof said member to move the valve head to open position, means forapplying a lower pressure against the other side of said member to urgeit to close the valve when said higher pressure drops to a pressureequal to and less than said lower pressure, manual means for rotatingsaid stem to actuate said cam means during opening and closing saidvalve, and means controlled by said manual means for venting said oneside of said pressure responsive means before the manual means is movedto hold said valve closed.

7. A liquid eduction device comprising a tank for storing liquefied gasin both its liquid and vapor phases, outlet means for said tankincluding a valve housing having a valve seat facing the tank incommunication with said tank at the bottom thereof and subjected to thehydraulic head of the liquid in said tank in addition to the pressure ofthe vapor thereon, a valve head closing against said valve seatincluding a stem, means for closing the valve including a resilientelement resiliently closing and a rotatable cam member for positivelyclosing the valve head, a liquid pump connected at its inlet to thevalve seat and having an outlet with a shut-off valve therein, a bleedpassage bypassing said valve head and seat for liquid priming of thepump inlet, pressure responsive means for reciprocating said valve stemincluding a diaphragm, means for applying to one side of the diaphragmliquid pressure from the output side of the pump to open said valveincluding a pilot shut-off valve, means for venting said liquid pressureincluding venting valves located on the tank remote from said valvehousing, means for applying to the other side of the diaphragm liquidpressure from the inlet of said pump to urge closure of the valve.

8. A quick acting cut-off filler-eduction valve comprising a valvehousing defining a passageway having a valve seat therein and an inletopening at the level of said valve seat, a valve head closing againstsaid seat, a valve stem journalled in said valve head against relativeaxial movement therewith to extend through the seat and reciprocallysupported in the housing above and below the valve head, means supportedby said housing above the valve head for closing the valve including acam rise having a detent at its top, a follower driven by said stem tooccupy said detent and lock the valve head in closed position and aresilient element urging said valve head to its closed position, a bleedconduit bypassing said valve and valve seat, pressure differentialresponsive means including a reciproeating member supported in thehousing at one side of said passageway and connected to the valve stem,means for applying a pressure higher than that present in the passagewayto one side of said reciprocating member to urge the stem to open thevalve, means for applying pressure in said passageway against the otherside of said reciprocating member to assist said resilient element tomove the stem to close the valve when said higher applied pressure dropsto the pressure present in said passageway, manual means for closingsaid valve including a rotatable supported wrenching member reciprocablyreceiving the end of the stem in visually exposed relationship when saidfollower is disposed in said detent, and valve means controlled by saidwrenching member for venting said one side of said pressure responsivemeans during the time said follower engages the incline of said camrise.

9. A liquid eduction device comprising a tank for storing liquefied gasin both its liquid and vapor phases, outlet cut-ofi valve means for saidtank having a pressure drop of less than one quarter pound per squareinch at full open flow including a valve housing having a passage with avalve seat of the same size as said passage and facing the tank incommunication with said tank at the bottom thereof and subjected to thehydraulic head of the liquid in said tank in addition to the pressure inthe tank, a valve head closing against said valve seat including arotatable stem, means for closing the valve including a resilientelement resiliently closing the valve head and a cam member operated byrotation of said stem for positively closing the valve head, a liquidpump connected at its inlet to the valve seat and having an outlet witha shutofi valve therein, a bleed passage bypassing said valve head andseat for liquid priming of the pump inlet, pres sure responsive meansfor reciprocating said valve stem including a diaphragm disposed to oneside of the passage, means for applying to one side of the diaphragmliquid pressure from the output side of the pump to open said valveincluding a pilot shut-off valve, means for venting said liquidpressure, means for applying to the other side of the diaphragm liquidpressure from the inlet of said pump to assist said resilient element tourge closure of the valve.

10. A liquid eduction device comprising a tank for storing liquefied gasin both its liquid and vapor phases, out let means for said tankincluding a valve housing having a passage therethrough and a valve seatat the top of the passage facing the tank in communication with saidtank at the bottom thereof and subjected to the hydraulic head of theliquid in said tank in addition to the pressure of the vapor thereon, avalve head closing against said valve seat including a stem, means forclosing the valve including a resilient element resiliently closing thevalve head, a liquid pump connected at its inlet to the passage andhaving an outlet with a shut-ofi valve therein, pressure responsivemeans for reciprocating said valve stem, means for applying to one sideof the pressure responsive means a liquid pressure from the output sideof the pump to open said valve, a small passage interconnecting theinterior of the tank with the other side of the pressure responsivemeans to oppose opening of the valve, valve means in said small passagefor closing said passage and venting said other side of the pressureresponsive means to permit opening of the valve.

11. The combination called for in claim 10 in which said valve meansincludes a manually opened valve closing with fluid flow from said otherside of the pressure responsive means and a valve element carrying saidmanually opened valve urged by pressure on said other side to opencommunication with said small passage.

12. A liquid eduction device comprising a tank for storing liquefied gasin both its liquid and vapor phases, outlet means for said tankincluding a valve housing having a passage therethrough and a valve seatof a predetermined area facing and in communication with said tank atthe bottom thereof and subjected to the hydraulic head of the liquid insaid tank in addition to the pressure of the vapor thereon, a valve headclosing against said valve seat including a stem, means for closing thevalve including a resilient element urging closure of the valve head,pres sure differential responsive means including a reciprocating memberconnected to the valve stem and having a pressure responsive areagreater than said predetermined area, means for applying pressurepresent in the passage to one side of said pressure responsive means tourge it to open the valve, means for venting to atmosphere the otherside of said pressure responsive means to permit opening of the valve bysaid pressure responsive means under the pressure applied to said oneside thereof, and manually controlled means for venting said one side ofsaid pressure responsive means to release said resilient element forclosing said valve.

13. A liquid eduction device for a tank storing liquefied 7 ll: t a gasin both its liquid and vapor ,phases, outlet means adapted to be securedto the bottom of the tank including a valve housing having a passagetherethrough and a valve seat of a predetermined area in communicationwith said tank at the bottom thereof, a valve head receivable withinsaid tank and closing against said valve seat including a stem having a.lower portion extending through said valve seat, means for closing thevalve including a resilient element urging closure of the valve head,pressure difierential responsive means including a diaphragm membersupported in said housing and connected to the lower portion of saidstem, said diaphragm having a pressure responsive area greater than saidpredetermined area, means for applying pressure present in the passageto the lower side of said diaphragm to'urge it to open the valve,'meansfor venting to atmosphere the upper side of said diaphragm to permitopening of the valve by said diaphragm under the pressure applied tosaid lower side thereof, and manually controlled means for venting said.lower side of said diaphragm to permit said resilient element to closesaid valve. 7

14. A liquid eduction device comprising a tank for storing liquefied gasin both its liquid and vapor phases, outlet means for said tankincluding a valve housing having a passage therethrough and a valve seatof a predetermined area facing and in communication with said tank atthe bottom thereof and subjected to the hydraulic head of the liquid insaid tank in addition'to the pressure of the vapor thereon, a valve headclosing against said valve seat includinga stem, means for closing thevalve including a resilient element urging closure of the valve head,pressure differential responsive means including a reciprocating memberconnected to the valve stem and having a pressure responsiveareatgreater than said predetermined area, means for applying pressurepresent in the'passage to one side of said pressure responsive means tourge it to No references cited.

M. CARY NELSON, Primary Examiner.

1. A LIQUID EDUCTION DEVICE COMPRISING A TANK FOR STORING LIQUEFIED GASIN BOTH ITS LIQUID AND VAPOR PHASES, OUTLET MEANS FOR SAID TANKINCLUDING A VALVE HOUSING HAVING A VALVE SEAT FACING THE TANK INCOMMUNICATION WITH SAID TANK AT THE BOTTOM THERE AND SUBJECTED TO THEHYDRAULIC HEAD OF THE LIQUID IN SAID TANK IN ADDITION TO THE PRESSURE INTHE TANK OF THE VAPOR THEREON, A VALVE MEMBER CLOSING AGAINST SAID VALVESEAT AND INCLUDING A ROTATABLE STEM, MEANS FOR CLOSING THE VALVEINCLUDING AN ELEMENT RESILIENTLY CLOSING THE VALVE MEMBER AND A CAMMEMBER OPERATED BY ROTATION OF SAID STEM FOR POSITIVELY CLOSING THEVALVE MEMBER, A LIQUID PUMP CONNECTED AT ITS INLET TO THE VALVE SEAT ANDHAVING AN OUTLET WITH A SHUT-OFF VALVE THEREIN, A BLEED PASSAGEBYPASSING SAID VALVE HEAD AND SEAT FOR LIQUID PRIMING OF THE PUMP INLET,PRESSURE RESPONSIVE MEANS FOR RECIPROCATING SAID VALVE STEM INCLUDING ADIAPHRAGM, MEANS FOR APPLYING TO ONE SIDE OF THE DIAPHRAGM LIQUIDPRESSURE FROM THE OUTPUT SIDE OF THE PUMP TO OPEN SAID VALVE ANDINCLUDING A SHUT-OFF VALVE, MEANS FOR VENTING SAID LIQUID PRESSURE, ANDMEANS FOR APPLYING TO THE OTHER SIDE OF THE DIAPHRAGM LIQUID PRESSUREFROM THE INLET OF SAID PUMP TO URGE CLOSURE OF THE VALVE.